1. Field of the Invention
This invention relates to an air pump apparatus for use primarily in a motorized two-wheeled vehicle.
2. Description of the Prior Art
One type of prior art air pump apparatus comprises a cylinder, extending forwards from a pump casing such as a crankcase or the like, having therein a cylinder liner and a piston mounted in the cylinder liner and arranged to be driven to reciprocate forwards and rearwards by a driving source such as an electric motor or the like. An air space is formed in front of the piston to serve as a pump chamber. It has been usual with this type of air pump that a lubrication oil such as grease or the like is applied to the piston at a portion thereof between the piston and the cylinder liner. However, this causes an undesirable result in which the compressed air produced contains the oil.